To provide a method that does not require a special device for replacement or a manual piston operation in changing a friction pad, operates an electric motor by simple operation, can easily return the piston to a position allowing easy replacement of the friction pad, and can easily change the friction pad.

This electric disk brake 71 is constituted so that a pair of friction pads 3 and 4 are disposed so as to face each other on both sides of a disk rotor 1, the electric motor 15 is operated by control from a controller 72, the piston 38 is moved to press and slide the pair of friction pads 3 and 4 to the disk rotor 1 to perform braking. In the replacement method for the friction pad, in exchanging the friction pads 3 and 4, in a detected state of vehicle stop by a vehicle stop detection means 75, the electric motor 15 is operated by control from an external controller 73 electrically connected to the controller 72 to return the piston 38 to the changeable position of the friction pads 3 and 4.